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Halogen Headlights


Scott Mckenzie
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Define "OK".  IIRC, stock lights are 37.5W/55W.  Those can heat up the switch pretty good.  Every extra bit of current is more heat.  Eventually you'll trip the breaker, but that seems to happen long after the point of heat-related damage.

 

Easy fix:

- Buy two standard 30A automotive relays.

- Run a fused 10ga. jumper from the power takeoff by the horn relay to terminal 30 of each relay.

- Connect terminal 85 of each relay to ground.

- Cut the tan (low beam) and light green (high beam) wires in the lighting harness somewhere around the battery/left front corner of the car. 

- Connect the dash side of each wire to terminal 86 of a relay.

- Connect the light side of each wire to terminal 87 of the same relay.

 

No more switch problems.

Edited by KongaMan (see edit history)
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7 hours ago, Scott Mckenzie said:

Just wondering if the Halogen  headlights are ok to use in my `64 .  I read somewhere that they can over heat the  light switch. Please advise, Scott

 

Hi Scott,

i put a set of 4 Ciebie QH lamps in my ‘63, not hi powered but just great lighting.

 

Tested out fine in the garage until I used them on the highway. ( when I really needed them ☹️☹️☹️☹️☹️☹️

 

Headlamp switch went into overload every time I used hi beam for any length of time( start flickering on and off) 

 

 Fix was to fit relays on both hi and Lo beam circuits and heavy 5mm cable for both power and earth wires.

 

Worth the effort.????

Rodney

 

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I did also put in relays and halogen light in my 1963 although I went a little bit crazy with 4 relays (2 for each side of the car) to minimize the risk for full darkness in case of of a relay or fuse failure. (Each of my relays have a replaceable fuse built in).

I am a lot more happy to drive after dark with this setup than the old original sealed beams.

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Make the ground connection to any convenient screw in the radiator support, etc.  Or, since you're so close to the battery, you can run a pigtail off the battery cable (if you don't mind the looks).

 

The simple answer on the fuse is that four stock high beams draw 12.5A ((4 * 37.5W)/12V), so you'd want a 15A fuse on the battery feed.

 

The more complete answer is that this solution doesn't consider voltage drop.  The wiring should be sized by capacity and acceptable voltage loss.  The stock harness uses 18 ga. wire for the low beams and 16 ga. wire for the high beams.  Two stock low beams at 55W each is a big load for 18 ga. wire.  Even using relays and the shorter wiring runs, you will see substantial voltage loss (i.e. dimmer lights) because of this smaller wire.  As such, a better solution is to upgrade the wire from the relays to the lamps, as the stock wiring is undersized for the job.

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4 hours ago, KongaMan said:

The simple answer on the fuse is that four stock high beams draw 12.5A ((4 * 37.5W)/12V), so you'd want a 15A fuse on the battery feed.

 

Yes. And if they are new sealed beams from the parts store (instead of the stock Buick ones), they are probably 50 watts each instead of 37.5. In that case upsize it to 20 amps.

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That is a pretty good load for automotive switching. If I did a conversion like that I think I would put a capacitor on the 12VDC entering the relay to reduce potential (no pun) arcing in the relay points. Might as well go that extra.

Bernie

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5 hours ago, surfgeek said:

Wait, what?  Where does the cap go in KongaMan's schematic? If this is DC what difference would a cap make?

 

I would put one at each of the #35 terminals. It would do a similar job to the one in the distributor.

 

Rolls-Royce cars have a bunch, on window switches, wiper contacts, signal light relays. It is overkill, but if you going to make the mod go all the way.

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For arc suppression, you typically use an RC (snubber) circuit across either the load or the switch contacts.  The purpose is to reduce the voltage spike when the relay opens.  This spike causes arcing, which, in turns, tends to burn the contacts.  In this case, you could put the snubber circuit between terminal 30 and terminal 87 of the relay:

 

headlight-relays-with-snubb.thumb.jpg.8f29b07c8951c774e284c9ae1fb574ed.jpg

 

Do you need it? I dunno; I can't remember the last time I had to replace a burned out relay, and -- among other uses -- I've been running a hot-rodded lighting harness for years in a different rig with 90W/145W bulbs.  You might get the same security by buying good relays instead of whatever POS Chinese crap is the cheapest on eBay.  OTOH, it can't hurt, and the components don't cost much.  

Edited by KongaMan (see edit history)
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10 hours ago, Bloo said:

 

Yes. And if they are new sealed beams from the parts store (instead of the stock Buick ones), they are probably 50 watts each instead of 37.5. In that case upsize it to 20 amps.

 

Good point.  But before you go crazy putting in aircraft landing lights or something that be seen from space, remember that your alternator needs to have enough oomph to power them.  As a practical matter, this might argue for switching from a 4-lamp system to a 2-lamp system.  Two 80/110W lamps might be preferable to four 50W high beams.  As discussed elsewhere, you could (with the addition of one more relay) convert the inner lights (the current high beams) to DRLs while simultaneously gaining the superior illumination of the higher-powered bulbs in  the current low beam sockets.

Edited by KongaMan (see edit history)
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                           My Riviera has the stock wiring harness for the lights and it has four halogen headlamps that were in

the car when I bought it. I don't drive my car a lot but on occasion I've used the headlamps for an hour and a half at a time with no

problems. My 69 GTO that I've owned for 46 years has had halogens in it since 1985 and I've used them many  many times over the years

with stock headlamp wiring and  I've had no problems. My 79 Trans Am came from the factory with halogens and it has no relays

to operate them, just the same old headlamp switch and dimmer switch to operate them, so I find this post very puzzling. Also over the years I've converted many of my customer's  old cars to halogen headlamps, and I never received any complaints regarding these type

of problems mentioned on this thread.

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2 hours ago, Seafoam65 said:

                           My Riviera has the stock wiring harness for the lights and it has four halogen headlamps that were in

the car when I bought it. I don't drive my car a lot but on occasion I've used the headlamps for an hour and a half at a time with no

problems. My 69 GTO that I've owned for 46 years has had halogens in it since 1985 and I've used them many  many times over the years

with stock headlamp wiring and  I've had no problems. My 79 Trans Am came from the factory with halogens and it has no relays

to operate them, just the same old headlamp switch and dimmer switch to operate them, so I find this post very puzzling. Also over the years I've converted many of my customer's  old cars to halogen headlamps, and I never received any complaints regarding these type

of problems mentioned on this thread.

I concur, I have encountered a headlight switch breaker opening when loaded a handful of times but the solution in every instance was a new headlight switch. Having said that, these situations did not involve headlights whose power consumption went beyond a typical halogen headlight. Before condemning the original engineering probably best to be sure the original components are up to snuff.

 Not mentioned in the additional engineering is the potential of adding possible points of failure in the revised system. Every connection and relay, which is a mechanical switch, is a potential point of failure. The KISS principle applies well here as headlights are a safety issue. That is why the manufacturer engineered an auto reset breaker into the original system. This is a somewhat minor point as the relays speced here in this thread are very reliable. Most all manufacturers have used them for years, so I have had complete immersion in servicing equipment which utilizes these relays. I consider them very reliable but have witnessed some failures. Most often I find they will produce an audible "click" but not switch current. This type of failure goes back to the addition of an anti arcing feature to protect the mechanical points in the relay.

  Tom

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3 hours ago, Seafoam65 said:

                           My Riviera has the stock wiring harness for the lights and it has four halogen headlamps that were in

the car when I bought it. I don't drive my car a lot but on occasion I've used the headlamps for an hour and a half at a time with no

problems. My 69 GTO that I've owned for 46 years has had halogens in it since 1985 and I've used them many  many times over the years

with stock headlamp wiring and  I've had no problems. My 79 Trans Am came from the factory with halogens and it has no relays

to operate them, just the same old headlamp switch and dimmer switch to operate them, so I find this post very puzzling. Also over the years I've converted many of my customer's  old cars to halogen headlamps, and I never received any complaints regarding these type

of problems mentioned on this thread.

 

One thing to consider is that halogen headlights don't necessarily consume any more power that normal sealed beams. That is, 50W is 50W.  Installing halogens doesn't imply a greater load on the wiring; it's just a more efficient technology (i.e. brighter light at the same power).

 

Another thing to consider is that most of the problems being discussed aren't readily apparent until it's too late.  You don't see the boogered switch or damaged wiring until it fails -- unless you happen to pull the switch out of the dash to look at it.  The 30A breaker in the switch is there to prevent catastrophic failure (e.g. a direct short), but it's far too large to prevent accumulated degradation due to using undersized wire.  If that breaker trips or flickers, it's generally because the owner has upgraded to more powerful lights (e.g. 4 90W high beams).  That, it turn, means even more stress on the switch and wiring.

 

Finally, a major problem that relays rectify is voltage loss.  No matter how you slice it, you lose voltage in the stock circuit (the heat that's toasting the wires and warming the switch is energy that could be lighting the lamps).  Lost voltage means less light.  If you use relays (and, ideally, properly sized wire) you'll get more light from the same lamps because you'll see higher voltage at the lamps.

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1 hour ago, 1965rivgs said:

I concur, I have encountered a headlight switch breaker opening when loaded a handful of times but the solution in every instance was a new headlight switch.

 

Ask yourself why the switch went bad.

 

1 hour ago, 1965rivgs said:

Having said that, these situations did not involve headlights whose power consumption went beyond a typical halogen headlight. Before condemning the original engineering probably best to be sure the original components are up to snuff.

 

As noted earlier, the breaker is far too large to trip from the load of 4 standard halogen lights.  The wiring and switch, however, are undersized for that same load.  Yes, it will work -- but the heat at the switch and the toasted wire and connectors are incontrovertible evidence of undersized components.

 

As an intellectual exercise, the curious reader might want to investigate the recommended wire gauge for 12' of wire for a 16A load (200W @ 12V).

 

1 hour ago, 1965rivgs said:

 Not mentioned in the additional engineering is the potential of adding possible points of failure in the revised system. Every connection and relay, which is a mechanical switch, is a potential point of failure. The KISS principle applies well here as headlights are a safety issue. That is why the manufacturer engineered an auto reset breaker into the original system. This is a somewhat minor point as the relays speced here in this thread are very reliable. Most all manufacturers have used them for years, so I have had complete immersion in servicing equipment which utilizes these relays. I consider them very reliable but have witnessed some failures. Most often I find they will produce an audible "click" but not switch current. This type of failure goes back to the addition of an anti arcing feature to protect the mechanical points in the relay.

 

If you do this properly (a separate fuse on each relay), one might argue that it's even more reliable than the stock system, which runs all lights through a single breaker.  Furthermore, if you switch to a 2-lamp system and repurpose the high beams to function as DRLs, you'll have a redundant backup system in the case both headlight relays fail.  That's three separate headlight circuits.  Or you could spend $3 and carry a spare relay. ;) 

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This might be a silly question, but would the use of LED bulbs eliminate some of the problems associated with Halogens seeing as how LEDs are soooo much more efficient and thus draw so much less juice?

 

I have yet to find a pair of LED bulbs which would fit in the location, but I'm always looking.  Most have a fan or heatsink behind the bulb which means you need more room back there.  There seems to be plenty of room for the high beams, but the low beams have less room on the battery side.

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